}

  public void testCheckPositive_positiveBigInteger() {
    MathPreconditions.checkPositive("BigInteger", BigInteger.ONE);
  }

  public void testCheckPositive_negativeBigInteger() {
    assertThrows(
        IllegalArgumentException.class,
        () -> MathPreconditions.checkPositive("BigInteger", BigInteger.ZERO.negate()));
  }

  public void testCheckNonNegative_zeroInt() {